Prepared roofing.



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H. E.BOARDMAN. l 0 PREPARED 000mm. A APPLICATION FILED NOV. 2. 1915. J

1,190,505.-` y ranwuuly 11, 1016-;

UNiTED STATES PATENT OFFICE.r

PREPARED BOOFIN Gr.

Specification of Letters Patent.

Patented July 11, 1916.

Application filed November 2, 1915. Serial No. 59,209.

To all whom t may concern.'

Be it known that I, HAROLD E. BOARD- MAN, a citizen of the UnitedStates, and resident of Medford, county of Middlesex, and State ofMassachusetts, have invented certain new and useful Improvements inPrepared Roofing, of which the following is a specification and whichare illustrated in the accompanying drawings, forming a part thereof.

The invention relates to prepared roofings which comprise a waterproofbody layer and a'protective and ornamental grit surface layer. The gritemployed for the surface layer of prepared roofings of this type hasheretofore been derived either from mineral substances having therequisite hardness or from4 waste products of similar character. In someinstances the grit is obtained by screening alone. More frequently,however, crushing is first required. In either case there is anobjectionable variation in the size and shape of the particles obtainedand difficulty is always experienced in removing the last traces ofdust. This dust is objectionable both because it interferes with theproper adhesion of the particles to the roof material hnd because itforms a thin coating upon the surface of each particle of grit andprevents the true color of the particles being shown. Furthermore, thesaid mineral substances and waste products are not obtainable in some ofthe colors which'j are particularly desirable for roof surfacingmaterials and while articial coloring has been proposed, the operationsincident thereto are expensive and the colors obtained are applied onlyto the surface of the particles and are generally not suiiicientlypermanent upon exposure to the weather.

The present invention accordingly contemplates the use of anartificially prepared grit which is free from dust and in which thesize, shape and color of the particles is definitely controlled, as bymoldingthe particles from a plastic mass.

The object of the invention is to provide a prepared roofing having agrit surface of improved appearance and weather resisting properties.

In the accompanying drawings, Figure 1 is a detail sectional view,showing a form of prepared roofing embodying the improvement provided bythe. invention, Fig. 2 is a detail plan view of the same, Fig. 3

is a side elevation showing the preferred .form of a. single particle ofthe grit surfacing material, greatly enlarged, and Fig. 4 is a detailsectional view showing a form of rollers which may be employed formolding the particles of grit surfacing. material. A j

In producing the improved prepared roofng, a body or foundation layer 10may be provided and this layer l0 is preferably rendered adhesive uponone side, as by the application thereto of a layerll of material whichis softened by heat. While the invention is not limited with referenceto the particular character lof the body layer 10, this layer maycomprise a sheet of well known roofing felt rendered waterproof by beingsaturated with asphalt. The layer 11 will then be conveniently composedof asphalt of such consistency as to be soft when moderately heated.

The improved prepared roofing also comprises the fire proof and weatherresisting grit surface layer 12. This last mentioned layer is formed bycovering the adhesive layer 11 with hardened particles 13, while theadhesive layer 11 is still soft. If dosired, the particles 13 may beforced into intimate contact with `the adhesive layer 11, as by passingthe completed sheet between pressure rolls.

' The particles 13 are preferably of uniform size and shape and willusually be of an attractive red or green color. These particles are mostconveniently prepared by being olded f stic com `o und and then hardenedby heat. A suitable-.plastic compound for this purpose ismduced bymiging owdered talc with uid silicate of so` a a ye 9i a p1 inept, a'soXid-'T'i'ron mi@ added to the cmpound when the partices are to becolored throughout. To provide for the molding of the particles in largequantities, at small expense, the plastic mass may be passed betweenrolls, as 14.-, 15, which have registering depressions 16, 17, formed intheir contacting surfaces in such numbers that closely relateddepressions extend over the entire surface of each roll. This operationwill usually serve for the complete separation of the plastic mass intoa quantity of the particles, as 13, or the mass may be formed into asheet in which the particles adhere together but in such manner as to bereadily broken apart.

While the particles 13 may take any mQlded shape, the weight of thequantity of particles required 'for the production of a given area ofthe grit surface layer 12 will vbe relatively small if the particles aresomewhat fiattened. As shown, each particle 13 -is molded in the form ofan oblate spheroid having a short axis as compared with its diameter. Inthis case the depressions 16, '17, are relatively shallow and eachdepression substantially conforms, in shape, with 1? one half of thefull. form of a single particle 13 The hardening of the molded particles13 may be accomplished b temertu of 1f a quantity of Water absorbentmaterial, as for example, Portland cement is included in thesaidfagm-ma'sT-L The molding of the particles 13 from a- 33 plastic massentirely eliminates the formation of dust. Each particle accordinglypresents a clear surface showing its true color and no fine material ispresent to interfere with the adhesion of the particles to thev asphaltlayer 11.. Furthermore, the materials employed in the production of theplastic mass are inexpensive and, as a Wide range of pigments may beemployed, a variety of colors are obtainable in the finished roofing.

I claim as my invention,-

1. A grit surface prepared roofing havingits said grit surface composedof artificially prepared hard spheroidal particles of uniform size.

2. A grit surface prepared roofing having its said grit surface composedof hardened particles molded from a plastic mass consisting of a mixtureof silicate of soda and a powdered substance containing silica.

3. A grit surface prepared roofing hav- 40 ing its said grit surfacecomposed of hardened particles molded from a plastic mass consisting ofa mixture of silicate of soda a powdered substance containing silica anda pigment. A

HAROLD E. BOARDMAN.

Copies of this patent may be obtained for ve cents each, by addressingthe Commissioner of Patents.

` Washington. D. C.

